JPS5950685B2 - Continuous polymerization method for thermoplastic resin - Google Patents

Description

【発明の詳細な説明】 本発明はモノビニル芳香族単量体およびエチレン姓不飽
和ニトリル単量体の混合溶液を重合原液とする熱町塑性
樹脂の連続塊状重合方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuous bulk polymerization of Natsumachi plastic resin using a mixed solution of a monovinyl aromatic monomer and an ethylenically unsaturated nitrile monomer as a polymerization stock solution.

従来、モ、／ビニル芳香族単量体およびエチレン住不飽
和ニトリル単量体からなる重合体の製造方法としては懸
濁重合、乳化重合、溶液重合、塊状重合などが知られて
いる。Conventionally, suspension polymerization, emulsion polymerization, solution polymerization, bulk polymerization, and the like have been known as methods for producing polymers composed of molybdenum/vinyl aromatic monomers and ethylene-containing unsaturated nitrile monomers.

これらの重合方法は得られる重合体の用途に応じて選択
されることもあるが、一般的には重合反応熱の除去およ
び重合反応の進行とともに増大する粘性物質の取扱いに
制約されて選択されているのが現状である。懸濁重合、
乳化重合、溶液重合はこの点有利な製造方法であるが、
使用する副原料による不純物の混入、水を分離する際の
排水負荷による環境汚染、または溶媒分離によるエネル
ギーロンなどの点から、省エネルギー、低公害の製造方
法では、今後製造プロセスとして採用することが問題と
なる方法である。Although these polymerization methods are sometimes selected depending on the intended use of the resulting polymer, they are generally selected based on the constraints of removing the heat of polymerization reaction and handling of viscous substances that increase as the polymerization reaction progresses. The current situation is that suspension polymerization,
Emulsion polymerization and solution polymerization are advantageous production methods in this respect, but
Energy-saving, low-pollution manufacturing methods have problems in adopting them in the future due to the contamination of impurities from the auxiliary raw materials used, environmental pollution due to wastewater load during water separation, and energy consumption due to solvent separation. This is the method.

また、塊状重合方法では、上記のような問題は解決され
るが、反応系の不安定住、重合反応の進行とともに上昇
する粘性物質の取扱い、規模の増大とともに増大する除
熱面積などの反応装置上の難問題がある。In addition, although the bulk polymerization method solves the above-mentioned problems, it also has problems with the reactor, such as instability of the reaction system, handling of viscous substances that increase as the polymerization reaction progresses, and heat removal area that increases as the scale increases. There is a difficult problem.

たとえば、重合率が５０〜６０％に到達した時点で重合
をやめ脱揮発装置に移行して揮発分をのＪ ぞいてポリ
マを得る方法（特公昭４８−２９７９７号公報、特公昭
５４−１４６２７号公報）が提案されている。For example, when the polymerization rate reaches 50 to 60%, the polymerization is stopped and transferred to a devolatilization device to remove volatile components to obtain a polymer (Japanese Patent Publications No. 48-29797, No. 54-14627). Public bulletin) has been proposed.

これらの方法は、揮発分をのぞくのに必要なエネルギー
を外部から与えており、装置が大きくな； るにつれて
、脱揮発装置が大きくなり、ばく大なエネルギーを要す
る。In these methods, the energy necessary to remove the volatile matter is supplied externally, and as the device becomes larger, the devolatilization device becomes larger and requires a large amount of energy.

そのために出来るだけ、ポリマの重合率を上げて省エネ
ルギー化を行なう必要がある。Therefore, it is necessary to increase the polymerization rate of the polymer as much as possible to save energy.

本発明者らは２槽プロセスによる効率的な方法を特公昭
４９−２６７号公報に提案した。The present inventors proposed an efficient method using a two-tank process in Japanese Patent Publication No. 49-267.

すなわら、第１反応器を完全混合槽とし、ここで重合率
を４０〜６５％まで上げたのら、プラグフロータイプの
第２反応器に供給して重合を完結させる方法である。こ
のプロセスにおいて、本発明者らはモノビニル芳香族−
エチレン住不飽和ニトリル共重合体を製造してきたが、
長期運転をしていくと、第２重合槽内に炭化ポリマが発
生する現象を起こし、該共重合体ペレツト中に混入して
出てくることがわかつた。In other words, the first reactor is used as a complete mixing tank, and after the polymerization rate is increased to 40 to 65%, the polymerization is completed by supplying the product to a plug flow type second reactor. In this process, we used monovinyl aromatic-
Although we have produced ethylene-based unsaturated nitrile copolymers,
It has been found that during long-term operation, a phenomenon occurs in which carbonized polymer is generated in the second polymerization tank, and is mixed into the copolymer pellets.

そのために数ケ月後には運転を中止し、槽内洗浄をしな
ければならなかつた。この炭化ポリマの生成原因を調査
したところ炭化ポリマの発生は滞留しやすい部分、例え
ば掻き取り翼の裏面、横棒のつけ根などに多くみられ特
に反応器下物に多いことが確認された。As a result, after several months, operation had to be stopped and the inside of the tank had to be cleaned. When we investigated the cause of the formation of carbonized polymer, we found that carbonized polymer is often found in areas where it tends to accumulate, such as the back of the scraping blade and the base of the horizontal bar, and is particularly prevalent in the bottom of the reactor.

すなわと異常滞留したポリマが高温において熱劣化しア
クリロニトリルの環化反応などを起し、炭化まですすん
だと思われる。In other words, it is thought that the abnormally accumulated polymer was thermally degraded at high temperatures and caused a cyclization reaction of acrylonitrile, leading to carbonization.

このため上記プロセスの生産性は当初子定していたもの
より大幅に低下せざるをえなかつた。For this reason, the productivity of the above process had to be significantly lower than originally estimated.

したがつて、本発明者らは第２反応器における圧力を特
定の条件で制御し、なおかつ特定の溶媒を特定量存在さ
せることによりポリマの品質をそこなうことなく、炭化
ポリマの生成を防止し、長期連続運転が可能な製造方法
を見出し、本発明に到達した。すなわら本発明は、モノ
ビニル芳香族単量体が６０〜９０％およびエチレン住不
飽和ニトリル単量体が１０〜４０％なる混合溶液を重合
原液とし、まず完全混合槽になるような攪拌装置で重合
し、次いでプラグフロータイプの反応器で重合を行なう
のに際し、プラグフロー反応器内の圧力を１〜５ｋ９／
ＣｌＴｌＧの範囲の一定圧力に保持し、反応器下部から
吐出される重合液中にモノビニル芳香族単量体の沸点に
対し−１５〜＋５℃の範囲の沸点を有する溶媒を（ｌ）
式から求められる量（ｘ）存在させてｘ：溶媒濃度（％
）ｐ：圧力（Ｋｇ／ｃ−１ｉ１Ｇ） 重合液の温度を１５０−１９０℃の範囲に制御し、次い
で重合液を脱揮発物装置において未反応モノマ、溶媒を
気化して、分離し、溶融ポリマを連続的に取出すことを
特徴とする熱町塑性樹脂の連続重合方法である。Therefore, the present inventors prevented the formation of carbonized polymer without impairing the quality of the polymer by controlling the pressure in the second reactor under specific conditions and by making a specific amount of a specific solvent exist. We have discovered a manufacturing method that allows for long-term continuous operation, and have arrived at the present invention. In other words, in the present invention, a mixed solution containing 60 to 90% of monovinyl aromatic monomer and 10 to 40% of ethylene-based unsaturated nitrile monomer is used as a polymerization stock solution, and first, a stirring device that becomes a complete mixing tank is used. When performing polymerization in a plug-flow type reactor, the pressure inside the plug-flow reactor is set at 1 to 5 k9/min.
The pressure is maintained at a constant pressure in the range of ClTlG, and a solvent (l) having a boiling point in the range of -15 to +5 °C relative to the boiling point of the monovinyl aromatic monomer is added to the polymerization liquid discharged from the bottom of the reactor.
The amount (x) determined from the formula is present x: solvent concentration (%
) p: Pressure (Kg/c-1i1G) The temperature of the polymerization solution is controlled in the range of 150-190℃, and then the polymerization solution is placed in a devolatilization device to vaporize and separate unreacted monomers and solvent, and the molten polymer is This is a method for continuous polymerization of thermoplastic resin, which is characterized by continuously taking out.

本発明で使用するモノビニル芳香族単量体はスチレン、
α−メチルスチレン、ビニルトルエン、クロルスチレン
などのスチレン系単量体であり、エチレン性不飽和二ト
リル単量体はアクリロニトリル、メタクリロニトリルな
どである。The monovinyl aromatic monomer used in the present invention is styrene,
Styrenic monomers such as α-methylstyrene, vinyltoluene, and chlorostyrene, and ethylenically unsaturated nitrile monomers such as acrylonitrile and methacrylonitrile.

モノビニル芳香族単量体とエチレン姓不飽和ニトリル単
量体の比は６０〜９０％対１０〜４０％であり、好まし
くは６５〜８０％対２０〜３５％が良い。また必要に応
じて他のビニル単量体、例えばメタクリル酸メチル、メ
タクリル酸エチル、アクリル酸メチル、アクリル酸エチ
ルなどの単量体を１０％以下含有しても差し支えない。
また、通常のラジカル重合の際に重合調節剤として添加
されるメルカプタン類、四塩化炭素などの有機ハロゲン
化物、ジスルフイド類などを添加してもよいし、必要に
応じて通常ラジカル重合に使用されている開始剤、例え
ばアゾビスイソブチロニトリル、アゾビスシクロヘキサ
ンニトリルなどのアゾ系開始剤、過酸化ベンゾイル、ラ
ウリルパーオキサイド、クメンハイドロパーオキサイド
、Ｔｅｒｔ−ブチルパーベンゾエードなどの有機過酸化
物を使用しても差し支えない。本発明の重合装置として
は２段階に分割したものを用いることが重要である。The ratio of monovinyl aromatic monomer to ethylenically unsaturated nitrile monomer is 60-90% to 10-40%, preferably 65-80% to 20-35%. Further, if necessary, other vinyl monomers such as methyl methacrylate, ethyl methacrylate, methyl acrylate, and ethyl acrylate may be contained in an amount of 10% or less.
In addition, mercaptans, organic halides such as carbon tetrachloride, disulfides, etc., which are added as polymerization regulators during normal radical polymerization, may be added, and if necessary, mercaptans, organic halides such as carbon tetrachloride, disulfides, etc., may be added. azo initiators such as azobisisobutyronitrile, azobiscyclohexanenitrile, organic peroxides such as benzoyl peroxide, lauryl peroxide, cumene hydroperoxide, tert-butyl perbenzoate, etc. It's okay to do that. It is important to use a polymerization apparatus of the present invention that is divided into two stages.

本発明を実施するために用いる代表的な製造装置の概略
図を第１図に示した。A schematic diagram of a typical manufacturing apparatus used to carry out the present invention is shown in FIG.

製造装置は第１反応器および第２反応器を脱揮発物装置
から構成される。ポリマの分子量分布および組成分布を
なるべく狭くして均一なポリマを連続的に取り出すため
には、第１反応器を完全混合槽になるような攪拌装置に
し、気相部の圧力を圧力制御機構１で制御して内温をコ
ントロールするとともに蒸発してくるモノマ蒸気を冷却
機構３で凝縮してモノマを反応系に還流させることが必
要である。The production apparatus consists of a first reactor, a second reactor, and a devolatilization device. In order to make the molecular weight distribution and composition distribution of the polymer as narrow as possible and to continuously take out a uniform polymer, the first reactor is made into a stirring device that serves as a complete mixing tank, and the pressure in the gas phase is controlled by a pressure control mechanism 1. It is necessary to control the internal temperature by controlling the internal temperature, and to condense the evaporated monomer vapor in the cooling mechanism 3 to reflux the monomer to the reaction system.

すなわら、第１反応器では反応温度を９５〜１３５゜Ｃ
圧力を０．５〜２．０ｋ９／ＣｌｌｌＧの条件下に制御
してポリマ濃度を５０〜７０％まで重合させることが望
ましい。That is, in the first reactor, the reaction temperature was set at 95 to 135°C.
It is desirable to control the pressure under the conditions of 0.5 to 2.0 k9/ClllG to polymerize the polymer concentration to 50 to 70%.

ポリマ濃度が５０％より低いと得られるポリマの均一性
が低くなり、品質上問題となる。If the polymer concentration is lower than 50%, the uniformity of the obtained polymer will be low, causing a quality problem.

またポリマ濃度が７０％をこえると重合液の粘度が増大
し、完全混合が困難となる。Furthermore, if the polymer concentration exceeds 70%, the viscosity of the polymerization liquid increases, making complete mixing difficult.

第１反応器を経た重合液は第２反応器に連続的に供給さ
れるが、ポリマ濃度が５０〜７０％まで重合されている
ため粘稠な液になつておりさらに第２反応器で重合され
ると粘度が上昇する。The polymerization liquid that has passed through the first reactor is continuously supplied to the second reactor, but since the polymer concentration has been polymerized to 50-70%, it has become a viscous liquid and is further polymerized in the second reactor. viscosity increases.

そのため第２反応器で第１反応器と同様な完全混合およ
び重合液の温度を一定に制御することは困難である。し
たがつて第２反応器において、内部重合液は反応器内を
″上層から下層にかけて水平方向への混合はあつても、
流れ方向への混合がないようなプラグフロータイプの移
動をせしめ、かつ重合液部分の壁面を多段に分割したジ
ヤケツトを設けて保温せしめることが必要である。Therefore, it is difficult to achieve complete mixing in the second reactor as in the first reactor and to control the temperature of the polymerization liquid at a constant level. Therefore, in the second reactor, even though the internal polymerization liquid is mixed horizontally from the upper layer to the lower layer in the reactor,
It is necessary to provide plug-flow type movement so that there is no mixing in the flow direction, and to provide heat insulation by providing a jacket in which the wall surface of the polymerization liquid portion is divided into multiple stages.

この反応器に使用するかきとり翼付攪拌装置９は上下混
合のすくないものが好ましく、円盤状の多孔板数枚を取
付け、壁面をかきとる様な翼がついている撹拌機が良い
。The stirrer 9 with scraping blades used in this reactor is preferably one that does not cause much vertical mixing, and is preferably a stirrer equipped with several disc-shaped perforated plates and blades that scrape the wall surface.

この攪拌機９を設けることにより、シヨートパスや逆混
合をおさえることができる。By providing this stirrer 9, shot passes and back mixing can be suppressed.

重合液は反応器を上層から下層にかけて移動すると共に
重合していく。The polymerization liquid is polymerized as it moves through the reactor from the upper layer to the lower layer.

この重合反応によつて発生する重合熱によつて重合液の
温度を上昇させるが、この温度勾配は重合液の佛点に沿
つて変化する。この重合液の気液平衡は一般的に（２）
式のように整理される。The temperature of the polymerization liquid is increased by the heat of polymerization generated by this polymerization reaction, and this temperature gradient changes along the temperature point of the polymerization liquid. The vapor-liquid equilibrium of this polymerization liquid is generally (2)
It is arranged like an expression.

（２）式 Ｐ（に（ＰＡ（Ｔ）＋Ｐｓ（Ｔ））（１−
φ）ＥＸｐ（φ＋０．４φ２）Ｐ：操作圧力０１Ｈｇ） ＰＡ：温度（Ｔ）でのエチレン性不飽和二トリル単量体
の分圧（ＴｎｍＨｇ）Ｐ８：温度（Ｔ）でのモノビニル
芳香族単量体の分圧（ＭｍＨｇ）φ：ポリマの体積分率
（ＶＯｌ／ＶＯｌ）（２）式から求められる佛点以上に
発生する重合熱による温度上昇があれば重合系の温度は
沸点で止まり、余剰の熱量はモノマの蒸発に使用される
。(2) Formula P(to(PA(T)+Ps(T))(1-
φ)EXp(φ+0.4φ2)P: Operating pressure 01Hg) PA: Partial pressure of ethylenically unsaturated nitrile monomer at temperature (T) (TnmHg) P8: Monovinyl aromatic monomer at temperature (T) Body partial pressure (MmHg) φ: Polymer volume fraction (VOl/VOl) If there is a temperature rise due to the heat of polymerization generated above the Buddha point calculated from equation (2), the temperature of the polymerization system will stop at the boiling point and there will be a surplus. of heat is used to evaporate the monomer.

重合系の沸点は（２）式からポリマ濃度だけでなくモノ
マの組成によつても異なる。一般にエチレン性不飽和二
トリル単量体の沸点はモノビニル芳香族単量体の沸点に
くらべて数１０℃低い。そのためノ重合液が反応器の上
層から下層にかけて進行していく時に余剰の重合熱によ
つてモノマが蒸発するとき、液相にあるエチレン性不飽
和二トリル単量体とモノビニル芳香族単量体の割合たり
気相に存在するエチレン性不飽和二トリル単量体の量の
割合は多くなる。From equation (2), the boiling point of the polymerization system differs not only depending on the polymer concentration but also on the monomer composition. Generally, the boiling point of an ethylenically unsaturated nitrile monomer is several tens of degrees lower than the boiling point of a monovinyl aromatic monomer. Therefore, when the monomer evaporates due to surplus polymerization heat as the polymerization liquid progresses from the upper layer to the lower layer of the reactor, the ethylenically unsaturated nitrile monomer and monovinyl aromatic monomer in the liquid phase The ratio of the amount of ethylenically unsaturated nitrile monomer present in the gas phase increases.

この現象により反応器の上層のモノマ組成中のエチレン
性不飽和二トリル単量体の割合は多くなり、下層のモノ
マ組成中のエチレン性不飽和二トリル単量体の割合は少
なくなる。Due to this phenomenon, the proportion of ethylenically unsaturated nitrile monomer in the monomer composition of the upper layer of the reactor increases, and the proportion of ethylenically unsaturated nitrile monomer in the monomer composition of the lower layer decreases.

そのため反応器内の重合系の温度変化はポリマ濃度だけ
で一義的に決まらず、モノマ組成の変化も考慮に入れな
ければならない。Therefore, temperature changes in the polymerization system in the reactor are not determined solely by the polymer concentration, but changes in monomer composition must also be taken into account.

このような現象を考慮してスチレン７５部、アクリロニ
トリル２５部からなる重合原液について組成が変わると
圧力Ｖｓポリマ濃度Ｖｓ沸点の関係が変化することを示
したものが第２図である。ある操作圧力下で第２反応器
の温度勾配は第２図のように変わるがこれは沸点上の変
化である。Taking this phenomenon into consideration, FIG. 2 shows that the relationship between pressure, polymer concentration, and boiling point changes when the composition of a polymerization stock solution consisting of 75 parts of styrene and 25 parts of acrylonitrile changes. Under a certain operating pressure, the temperature gradient in the second reactor changes as shown in Figure 2, which is a change in boiling point.

重合率が高くなるにつれて重合速度は極端に低下し、重
合熱で反応液の温度を沸点上まで上昇させることができ
なくなり、沸点からずれてくるのが通常である。実際の
重合系で沸点からずれる条件をさがすのは困難であるが
、第２図の組成の場合で操作圧力２ｋ９／〜Ｇでポリマ
濃度９５％前後であり、この時の温度は１９５℃であつ
た。As the polymerization rate increases, the polymerization rate decreases extremely, and the temperature of the reaction solution cannot be raised above the boiling point due to the heat of polymerization, and the temperature usually deviates from the boiling point. It is difficult to find conditions that deviate from the boiling point in an actual polymerization system, but in the case of the composition shown in Figure 2, the operating pressure is 2k9/~G, the polymer concentration is around 95%, and the temperature at this time is 195°C. Ta.

このときの操作条件下で１９５℃以下の領域では重合系
は気相と液相の佛騰した状態で沸点上にあるが、１９５
゜Ｃより高くなる領域では佛点以下になり均一な液相の
状態であるといえる。Under the operating conditions at this time, in the region below 195°C, the polymerization system is in a state where the gas phase and liquid phase rise and are above the boiling point.
In the region where the temperature is higher than °C, the temperature is below the Buddha point and can be said to be in a uniform liquid phase state.

第２反応器から連続的に安定して重合液を吐出させるた
めには系の変動も考慮して完全に均一液相状態になる時
点まで重合させて取り出さなければならない。In order to continuously and stably discharge the polymerization liquid from the second reactor, it is necessary to polymerize the polymerization liquid until it reaches a completely uniform liquid phase state, taking into account fluctuations in the system, and then discharge the polymerization liquid from the second reactor.

そのため操作圧力２．０ｋｇ／０Ｔ！１Ｇでは重合物の
温度が２００℃前後になつた時点で吐出している。すな
わら第２反応器の液相部の温度は１２『Ｃから２０『Ｃ
まで変化しており、ジヤケツト温度についても多段保温
機構１０で内温に合わせて制御している。Therefore, the operating pressure is 2.0kg/0T! At 1G, the polymer was discharged when the temperature of the polymer reached around 200°C. That is, the temperature of the liquid phase of the second reactor ranges from 12'C to 20'C.
The jacket temperature is also controlled by the multi-stage heat retention mechanism 10 in accordance with the internal temperature.

し力山、この条件下で重合を続けていくと滞留しやすい
部分に炭化ポリマが生成し、ある大きさに成長すると剥
離し、吐出ポリマ中に異物として出てくることがわかつ
た。Shirikiyama discovered that if polymerization continues under these conditions, carbonized polymer will form in areas where it tends to stagnate, and when it grows to a certain size, it will peel off and come out as foreign matter in the discharged polymer.

この炭化ポリマは異常滞留したポリマが高温において熱
劣化し炭化まですすんだものと思われる。It is thought that this carbonized polymer was caused by the abnormally accumulated polymer thermally deteriorating at high temperatures and even carbonizing.

そのため炭化ポリマの発生がある程度多くなると重合を
中止し、槽内を空にして洗浄後人力で炭化ポリマを剥離
させてから又再スタートを実施していた。この停止によ
り、生産曲は大幅に低下し、連続重合の優位性を保つこ
とができなかつたが、第２反応器の下部温度を１５０で
Ｃ〜１９０℃、好ましくは１５００Ｃ〜１７０℃に制御
することによつて、この炭化ポリマの生成を防止するこ
とができた。しかしながら第２反応器の下部を１５０℃
〜１９０℃の範囲に制御して吐出することは上述したよ
うに液相と気相の沸騰状態の重合液を吐出することにな
り、吐出ポンプの定量住が悪化し、安定して吐出するこ
とはできない。Therefore, when a certain amount of carbonized polymer is generated, the polymerization is stopped, the tank is emptied, the carbonized polymer is peeled off manually after cleaning, and then restarted. Due to this stoppage, the production temperature was significantly reduced and the advantage of continuous polymerization could not be maintained, but the temperature at the bottom of the second reactor was controlled at 150C to 190C, preferably 1500C to 170C. In particular, the formation of this carbonized polymer could be prevented. However, the lower part of the second reactor was heated to 150°C.
As mentioned above, controlling and discharging within the range of ~190°C means discharging boiling polymerization liquid in the liquid phase and gas phase, which deteriorates the constant flow rate of the discharge pump and results in stable discharge. I can't.

このため第２反応器内の重合状態が変動し、品質の変動
をもたらし、一定の品質の製品を製造することが困難と
なる。それゆえ重合液が液相のみで存在している状態に
しなければならない。As a result, the polymerization state within the second reactor fluctuates, leading to fluctuations in quality and making it difficult to manufacture products of constant quality. Therefore, the polymerization solution must exist only in a liquid phase.

この状態をつくりだすためにはモノマを溶媒で希釈して
いき、重合するモノマの量を減少させることである。極
端にいうと重合液が１５００Ｃ〜１９０℃の時点で重合
するモノマが存在しなければ、重合液に与える熱がなく
なり、操作圧力下での沸点以下の温度であれば、完全に
液相になり、吐出は安定する。To create this state, the monomer is diluted with a solvent to reduce the amount of monomer that polymerizes. In extreme terms, if there is no monomer to polymerize when the polymerization solution reaches 1500C to 190℃, there will be no heat given to the polymerization solution, and if the temperature is below the boiling point under operating pressure, it will completely become a liquid phase. , the discharge becomes stable.

したがつて、操作圧力はｌ〜 ５ｋ９／−Ｇの範囲内で
モノビニル芳香族単量体の沸点に対し−１５〜＋５゜Ｃ
の範囲の沸点を有する溶媒を（１）式から求まる量（ｘ
）を添加することにより反応器下剖の温度を１５０−１
９０℃に制御でき安定した吐出が可能になる操作圧力は
ｌ〜 ５ｋ９／−Ｇの範囲が好ましく、１ｋｇ／Ｃｒｌ
ｌＧより低いと、重合液が高粘度のため供給ポンプへの
噛み込み性が低く、吐出能力が低下する。また操作圧力
を５ｋｇ／−Ｇより高くすると反応器下部の温度を１５
０〜１９０℃に制御するためには溶媒量が多量に必要に
なり、装置効率が低下するとともに脱揮発物装置の脱葎
行ヒカを大きくしなければならず、２機以上の設備が必
要となつてくる。使用する溶媒はモノビニル芳香族単量
体の沸点に対し−１５〜 ５゜Ｃの範囲の沸点を有する
ものであることが好ましい。Therefore, the operating pressure is -15 to +5°C relative to the boiling point of the monovinyl aromatic monomer within the range of 1 to 5k9/-G.
The amount of solvent (x
) to lower the temperature of the reactor to 150-1
The operating pressure that can be controlled at 90°C and allows stable discharge is preferably in the range of 1 to 5k9/-G, and 1kg/Crl.
If it is lower than 1G, the polymerization liquid has a high viscosity and therefore has a low tendency to get caught in the supply pump, resulting in a decrease in discharge capacity. In addition, when the operating pressure is higher than 5 kg/-G, the temperature at the bottom of the reactor decreases to 15 kg/-G.
In order to control the temperature between 0 and 190°C, a large amount of solvent is required, which reduces the efficiency of the device and requires a large devolatilization device, which requires two or more equipment. I'm getting old. The solvent used preferably has a boiling point in the range of -15 to 5°C relative to the boiling point of the monovinyl aromatic monomer.

たとえば、ジプロピルケトン、エチルベンゼン、キシレ
ン、バレロニトリル、ブチルエーテルなどがあげられる
。Examples include dipropyl ketone, ethylbenzene, xylene, valeronitrile, and butyl ether.

モノビニル芳香族単量体の沸点より１５℃以上低い沸点
の溶媒を使用すると溶媒を所定量添加しても、溶媒は第
２反応器上部に蓄積し、定量的に反応器下部から重合液
と共に吐出されない。If a solvent with a boiling point 15°C or more lower than the boiling point of the monovinyl aromatic monomer is used, even if a predetermined amount of solvent is added, the solvent will accumulate in the upper part of the second reactor and be quantitatively discharged from the lower part of the reactor together with the polymerization liquid. Not done.

すなわら第２反応器内を溶媒で希釈していき、最後には
多量の溶媒を含む重合液を吐出することになり、操作圧
力を５ｋ９／粛Ｇより高く上げて運転することと同じに
なる。また溶媒の沸点がモノビニル芳香族単量体の沸点
より５℃以上高い沸点のものだと（１）式の範囲の添加
量では第２反応器下部の温度が１５０〜１９００Ｃ以上
になり改善効果がなくなる。また１５０〜１９０℃の範
囲に制御するためにはまた多量の添加量が必要となる。
また上記高沸点の溶媒は脱揮発物装置での脱気住が悪く
なり、揮発物の少ない樹脂を得るために脱揮発物装置の
能力を過大に大きくしなければならなくなる。この第２
反応器は第１反応器と同様に蒸発してくるモノマ、溶媒
、水などを凝縮、水分離、還流せしめる装置を用いるこ
とができる。第２反応器からでた重合物は次に脱揮発物
装置に入れられ未反応モノマ、溶媒を気化して分離させ
るが、この脱揮発物装置として特に多段ベント押出機が
好ましい。In other words, the inside of the second reactor will be diluted with the solvent, and in the end, a polymerization liquid containing a large amount of solvent will be discharged, which is equivalent to raising the operating pressure higher than 5K9/G. Become. Furthermore, if the boiling point of the solvent is 5°C or more higher than the boiling point of the monovinyl aromatic monomer, the temperature at the bottom of the second reactor will be 150 to 1900°C or more when added in the range of formula (1), resulting in no improvement effect. It disappears. Further, in order to control the temperature within the range of 150 to 190°C, a large amount of addition is required.
In addition, the above-mentioned high boiling point solvent makes it difficult to degas the solvent in the devolatilization device, and the capacity of the devolatilization device must be excessively increased in order to obtain a resin with low volatile content. This second
As the reactor, a device that condenses, separates water, and refluxes evaporated monomers, solvents, water, etc., as in the first reactor, can be used. The polymer produced from the second reactor is then placed in a devolatilization device to vaporize and separate unreacted monomers and solvents, and a multi-stage vent extruder is particularly preferred as this devolatilization device.

このベント押出機で未反応モノマ、溶媒などを気化させ
るとき除去効率を良くするためにベントロ手前に水注入
口を設けて水を添加しても良い。In order to improve removal efficiency when unreacted monomers, solvents, etc. are vaporized using this vent extruder, a water inlet may be provided in front of the vent to add water.

また必要ならは安定剤などの添加剤を混練することもで
きる。気化した未反応モノマ、溶媒は精製分離して再使
用することができるが混合液のまま第２反応器に戻して
再循環使用する方が良い。Additionally, additives such as stabilizers can be kneaded if necessary. The vaporized unreacted monomer and solvent can be purified and separated and reused, but it is better to return the mixed liquid to the second reactor and recycle it.

脱揮発物装置から連続的に取り出されるポリマは切断し
てペレツト状となし次の加工段階に供してもよいが、ま
た直接シートなどに連続成形しても良い。The polymer continuously removed from the devolatilization device may be cut into pellets for subsequent processing steps, or may be directly continuously formed into sheets or the like.

本発明方法により長時間の連続操業が安定して可能であ
り、得られたポリマは色調が良好で、強度なものである
。The method of the present invention allows stable continuous operation for long periods of time, and the obtained polymer has a good color tone and is strong.

以下実施ャリにより本発明をさらに詳述する。The present invention will be explained in further detail by the following examples.

なお実施例中の部数は重量部数を示すものである。実施
例 １第１図に示した如く配置した重合装置を用いて重
合を行なつた。Note that the numbers in the examples indicate parts by weight. Example 1 Polymerization was carried out using a polymerization apparatus arranged as shown in FIG.

スチレン７０部、アクリロニトリル３０部、ノルマルオ
クチルメルカプタン０．１５部の混合溶液を１００ｋｇ
／Ｈｒの速度で第１反応器に供給し４００ｋｇ供給した
ところで、供給を止め、圧力１．４ｋ９／ＤＧｌ内温１
２０℃に徐々にあげていき、一定になつてから、約４時
間後ポリマ濃度５５％に到達したところで、上記混合モ
ノマの供給および第２反応器・＼の連続供給を開始した
。それと同時に佛点１３６．２のＣのエチルベンゼンを
７ｋｇ／Ｈｒで第２反応器・＼供給し、４時間後工チル
ベンゼンの供給だけを停止した。下部温度は１７２℃に
なつており、ただらに第２反応器の下部の吐出ポンプお
よびベント押出機を作動させた。各ベントロはそれぞれ
減圧して未反応モノマ、エチルベンゼン、水を除去し、
溶融ポリマをカット状に押出し、切断して透明な樹脂ペ
レツトを得た６０ベントロから除去された未反応モノマ
、エチルベンゼンは凝縮後、第２反応器・＼再循環した
。この循環量は１７．０ｋｇ／Ｈｒ゛であり、このうら
エチルベンゼン量は６．９ｋｇ／Ｈｒであつた。この状
態の運転を約１ク明続けたが特に問題なく炭化ポリマは
ペレツト中にみられなかつた。得られたＡｓポリマのΩ
は０．５４〜０．５８の範囲内にあり色調はＹ値で１〜
３であつた。その後さらにｌケ月経過してから運転を中
止し、空槽化した第２反応器の内部を点検したが、炭化
ポリマらしきものの存在は確認することができなかつた
。100 kg of a mixed solution of 70 parts of styrene, 30 parts of acrylonitrile, and 0.15 parts of normal octyl mercaptan
/Hr to the first reactor, and when 400 kg was supplied, the supply was stopped and the pressure was 1.4k9/DGl internal temperature 1
The temperature was gradually raised to 20° C., and after about 4 hours, when the polymer concentration reached 55%, the supply of the mixed monomers and the continuous supply of the second reactor were started. At the same time, ethylbenzene with a Fos point of 136.2 C was fed to the second reactor at a rate of 7 kg/hr, and after 4 hours only the feed of ethylbenzene was stopped. The temperature in the lower part had reached 172°C, and the discharge pump and vent extruder in the lower part of the second reactor were operated. Each ventro is depressurized to remove unreacted monomers, ethylbenzene, and water.
The molten polymer was extruded into cuts and the unreacted monomer, ethylbenzene, removed from the 60-bento tube, which was cut to obtain transparent resin pellets, was condensed and recycled to the second reactor. The amount of circulation was 17.0 kg/Hr, and the amount of ethylbenzene was 6.9 kg/Hr. Operation in this state continued for about one day, but there were no particular problems and no carbonized polymer was found in the pellets. Ω of the obtained As polymer
is within the range of 0.54 to 0.58, and the color tone is Y value 1 to
It was 3. After one month had passed, the operation was stopped and the inside of the empty second reactor was inspected, but the presence of anything that looked like carbonized polymer could not be confirmed.

比較例 １ エチルベンゼンを第２反応器へ供給しないこと以外は全
て実施例１と同様に重合を行なつた。Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that ethylbenzene was not supplied to the second reactor.

第２反応器の下部温度は１９５℃から２００。Ｃの範囲
にありベント押出機から除去される未反応モノマは８．
７ｋｇ／Ｈｒであつた。この条件下で運転を１ケ月つづ
けていくとベレツトの中に赤褐色から黒色の異物の存在
が確認され、２ケ月目には５ｋｇ中に３５ケの炭化ポリ
マが存在していることを確認したため、運転を中止して
空槽化し、第２反応器の内部を観察した。The temperature at the bottom of the second reactor is 195°C to 200°C. Unreacted monomers in the range C and removed from the vent extruder are 8.
It was 7kg/Hr. After continuing to operate under these conditions for one month, the presence of reddish brown to black foreign matter was confirmed in the beret, and in the second month, it was confirmed that 35 pieces of carbonized polymer were present in 5 kg. The operation was stopped, the tank was emptied, and the inside of the second reactor was observed.

攪拌軸の翼および内部壁面に０．１〜３Ｗ！ｌの厚みで
炭化ポリマが生成、付着していることがわかつた。ノ この運転で得られたＡｓポリマのΩ＝０．５４〜０．５
８の範囲内であり、ＹＩ値は５〜７であつた。0.1-3W on the stirring shaft blades and internal wall surface! It was found that carbonized polymer was formed and adhered at a thickness of 1. Ω of the As polymer obtained by this operation = 0.54 to 0.5
8, and the YI value was 5-7.

比較例 ２エチルベンゼンを第２反応器に供給せず、か
つ第２反応器の下部温度を１７２℃に保つ以外は全て実
施例１と同様に重合を行つた。Comparative Example 2 Polymerization was carried out in the same manner as in Example 1, except that ethylbenzene was not supplied to the second reactor and the temperature at the bottom of the second reactor was maintained at 172°C.

第２反応器の下部温度を１７２℃に保つためには、第２
反応器の内圧を１１＜９／ＣｄＧ以下にしなければなら
ず、下部温度を１７２℃に保ら続けるためには吐出に使
用しているギヤポンプの回転数を所定の１．５〜２．０
倍以上にあげねばならなかつた。In order to maintain the temperature at the bottom of the second reactor at 172°C, it is necessary to
The internal pressure of the reactor must be kept below 11<9/CdG, and in order to maintain the lower temperature at 172°C, the rotational speed of the gear pump used for discharge must be set at a predetermined level of 1.5 to 2.0.
I had to give more than twice as much.

また定量性が悪く、吐出量の変動が大きいためベント押
出機のベントロからポリマがベントアツプするのを防ぐ
ため各ベントの真空度を変更しなければならなく、得ら
れたペレツトの揮発分は０．５〜２．０％と大きく変動
しており、とてもそのまま成形材料に使用できるもので
はなかつた。実施例 ２実施例１においてエチルベンゼ
ンのかわりに、沸点１３８．４℃のＰ−キシレンを使用
して実施例１と同様の方法で重合した。In addition, the quantitative performance is poor and the discharge rate fluctuates widely, so the vacuum degree of each vent must be changed to prevent the polymer from venting up from the vent of the vent extruder, and the volatile content of the pellets obtained is 0. The content varied widely, ranging from 5 to 2.0%, and could not be used as a molding material as it was. Example 2 Polymerization was carried out in the same manner as in Example 1 except that P-xylene having a boiling point of 138.4° C. was used in place of ethylbenzene.

実施例１と同様に安定して連続重合を行なうことができ
、約１ケ月半ほど運転して停止したが、第２反応器内部
は炭化ポリマはほとんどみられず、ペレツト中にも炭化
ポリマの存在を発見することができなかつた。As in Example 1, continuous polymerization could be carried out stably, and the operation was stopped after about a month and a half, but almost no carbonized polymer was found inside the second reactor, and no carbonized polymer was found in the pellets. I could not discover its existence.

このときのポリマのΩ二０．５５〜０．５６でありペレ
ツトの色調はＹＩ＝１〜３であつた。At this time, the Ω of the polymer was 0.55 to 0.56, and the color tone of the pellet was YI = 1 to 3.

比較例 ３ 実施例１においてエチルベンゼンのかわりに佛点７９．
６おＣのメチルエチルケトンを使用して実施例１と同様
の方法で重合した。Comparative Example 3 In Example 1, Butsu point 79. was used instead of ethylbenzene.
Polymerization was carried out in the same manner as in Example 1 using 6-C methyl ethyl ketone.

第２反応器に供給開始してから４時間後、メチルエチル
ケトンの供給のみ停止したが第２反応器下部の温度は２
００℃であり、さらに上昇の傾向をみせていたので、ま
たメチルエチルケトンの供給を再開した。Four hours after the start of supply to the second reactor, only the supply of methyl ethyl ketone was stopped, but the temperature at the bottom of the second reactor was 2.
Since the temperature was 00°C and was showing a tendency to rise further, the supply of methyl ethyl ketone was restarted.

また第２反応器の吐出ポンプベント押出機も作動させ、
連続重合を行なつた。第２反応器下部の温度は一旦２１
０℃まで上昇したが４時間後に温度がさがりはじめ１９
０昇Ｃにまで下がつたのでメチルエチルケトンの供給を
再び停止した。この時点前後からベントロから除去され
る量が多くなり、ベントアツプしはじめた。The discharge pump vent extruder of the second reactor is also operated,
Continuous polymerization was carried out. The temperature at the bottom of the second reactor was once 21
The temperature rose to 0℃, but after 4 hours the temperature started to drop19
Since the temperature had dropped to 0 C, the supply of methyl ethyl ketone was stopped again. Around this point, the amount removed from the ventro increased and the vent began to rise.

さらに２時間後にはベントロはベントアツプしたポリマ
で閉塞され、連続運転を中止せざるを得なかつた。After another two hours, the vent hole became blocked with vented polymer, and continuous operation had to be stopped.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の熱町塑性樹脂の連続重合反応装置の概
略図である。 第２図はスチレン７５部、アクリロニトリル２５部から
なる重合原液が重合するにつれて変化する沸点、圧力、
ポリマ濃度の関係図である。１・・・・・・圧力制御機
構、２・・・・・・加温機構、３・・・・・・冷却機構
、４・・・・・・ギヤポンプ、５・・・・・・水分離器
、６・・・・・・還流モノマポンプ、７・・・・・・圧
力制御機構、８・・・・・・冷却機構、９・・・・・・
多孔板付かきとり翼形攪拌装置、１０・・・・・・多段
保温機構、１１・・・・・・脱揮発物装置。FIG. 1 is a schematic diagram of a continuous polymerization reaction apparatus for a thermoplastic resin according to the present invention. Figure 2 shows the boiling point and pressure that change as a polymerization stock solution consisting of 75 parts of styrene and 25 parts of acrylonitrile is polymerized.
It is a relationship diagram of polymer concentration. 1...Pressure control mechanism, 2...Heating mechanism, 3...Cooling mechanism, 4...Gear pump, 5...Water separation 6...reflux monomer pump, 7...pressure control mechanism, 8...cooling mechanism, 9...
Scraping blade type stirring device with perforated plate, 10... Multi-stage heat retention mechanism, 11... Devolatilization device.

Claims (1)

【特許請求の範囲】 １ モノビニル芳香族単量体が６０〜９０％およびエチ
レン性不飽和ニトリル単量体が１０〜４０％なる混合溶
液を重合原液とし、まず完全混合槽になるような攪拌装
置で重合し、次いでプラグフロータイプの反応器で重合
を行なうのに際し、プラグフロー反応器内の圧力を１〜
５ｋｇ／ｃｍ＾２Ｇの範囲の一定圧力に保持し、反応器
下部から吐出される重合液中にモノビニル芳香族単量体
の沸点に対し−１５〜＋５℃の範囲の沸点を有する溶媒
を（１）式から求められる量（ｘ）存在させて（１）式
［２／３］ｐ＋［４／３］≦ｘ≦［１４／３］Ｐ＋［４
／３］ｘ：溶媒濃度（％）Ｐ：圧力（ｋｇ／ｃｍ＾２Ｇ
） 重合液の温度を１５０〜１９０℃の範囲に制御し、次い
で重合液を脱揮発物装置において未反応モノマおよび溶
媒を気化して、分離し、溶融ポリマを連続的に取出すこ
とを特徴とする熱可塑性樹脂の連続重合方法。[Scope of Claims] 1. A stirring device that uses a mixed solution of 60 to 90% of monovinyl aromatic monomer and 10 to 40% of ethylenically unsaturated nitrile monomer as a polymerization stock solution, which first becomes a complete mixing tank. When performing polymerization in a plug flow type reactor, the pressure inside the plug flow reactor is set to 1 to 1.
The pressure was maintained at a constant pressure in the range of 5 kg/cm^2G, and a solvent (1 ) The quantity (x) found from the formula (1) exists and the formula [2/3]p+[4/3]≦x≦[14/3]P+[4
/3] x: Solvent concentration (%) P: Pressure (kg/cm^2G
) The temperature of the polymerization liquid is controlled in the range of 150 to 190°C, and then the unreacted monomer and solvent are vaporized and separated from the polymerization liquid in a devolatilization device, and the molten polymer is continuously taken out. Continuous polymerization method for thermoplastic resins.